Why can't I call "GetDistance" from within my dll? : IV

» Thu Apr 14, 2016 4:07 am

Everyone is really busy, so I don't want to bug anyone specifically. So if anyone sees this and has an answer, that would be swell.

I'm trying to utilize "GetDistance" from within my .dll. I'm using OBSE 21 source code.

I found this section of code in GameOjects.h (see third line from the bottom)

Spoiler

// 058
class TESObjectREFR : public TESForm
{
public:
#if OBLIVION
	MEMBER_FN_PREFIX(TESObjectREFR);
	DEFINE_MEMBER_FN(IsOffLimitsToPlayer, bool, kTESObjectREFR_IsOffLimitsToPlayerAddr);
#endif

	enum
	{
		//	TESForm flags
		//	if(!IsActor())
				kChanged_IsEmpty =		0x00010000,
					// CHANGE_OBJECT_EMPTY
					// no data?

		kChanged_Inventory =			0x08000000,
			// CHANGE_REFR_INVENTORY
			// ### todo: see 0048BA40

		//	if((changed & ((version < 0x43) ? 0x177577F0 : 0x177577E0))) || IsActor())
		//	{
		//		// this is all part of its own function
		//
		//	}

		//	if(!IsActor())
				kChanged_Animation =	0x02000000,
					// CHANGE_REFR_ANIMATION
					// UInt16	dataLen;
					// UInt8	data[dataLen];
		kChanged_Move =			0x00000004,
			// TESObjectCELL	cell
			// float			pos[3]
			// float			rot[3]
		kChanged_HavokMove =			0x00000008,
			// CHANGE_REFR_HAVOK_MOVE
		kChanged_MapMarkerFlags =		0x00000400,
			// CHANGE_MAPMARKER_EXTRA_FLAGS
		kChanged_HadHavokMoveFlag =		0x00000800,
			// CHANGEFLAG_REFR_HAD_HAVOK_MOVE_FLAG
			// if either of these are set
			// UInt16	dataLen;
			// UInt8	data[dataLen];

		//	if(version > 0x43)
				kChanged_Scale =		0x00000010,
					// CHANGE_REFR_SCALE
					// float	scale;

		kChanged_DoorOpenDefaultState =	0x00040000,
			// CHANGE_DOOR_OPEN_DEFAULT_STATE
			// no data

		kChanged_DoorOpenState =		0x00080000,
			// CHANGE_DOOR_OPEN_STATE
			// no data

		kChanged_DoorExtraTeleport =	0x00100000,
			// CHANGE_DOOR_EXTRA_TELEPORT

		kChanged_ExtraOwner =			0x00000080,
			// CHANGE_OBJECT_EXTRA_OWNER
	};

	enum
	{
		kFlags_Persistent	= 0x00000400,		//shared bit with kFormFlags_QuestItem
		kFlags_Disabled =	  0x00000800,
		kFlags_Unk00000002	= 0x00000002,		// set when an item reference is picked up by an actor
		kFlags_Deleted		= 0x00000020,		// refr removed from .esp or savegame
		kFlags_Unk128		= 0x80000000,
		kFlags_Temporary	= 0x00004000,

		// both flags are set when an item picked up from gameworld
		// one or the other flag by itself is not sufficient
		kFlags_Taken		= kFlags_Deleted | kFlags_Unk00000002
	};

	TESObjectREFR();
	~TESObjectREFR();

	virtual void	Unk_37(void) = 0;
	virtual void	Unk_38(void) = 0;	// 38
	virtual void	Unk_39(void) = 0;
	virtual void	Unk_3A(void) = 0;
	virtual float	GetScale(void) = 0;
	virtual void	GetStartingAngle(float * pos) = 0;
	virtual void	GetStartingPos(float * pos) = 0;
	virtual void	Unk_3E(void) = 0;
	virtual void	Unk_3F(void) = 0;
	virtual void	RemoveItem(TESForm* toRemove, BaseExtraList* extraList, UInt32 unk2, UInt32 unk3, UInt32 unk4, TESObjectREFR* destRef,
		UInt32 unk6, UInt32 unk7, UInt32 unk8, UInt8 unk9) = 0;	// 40 unk2 quantity?
	virtual void	Unk_41(void) = 0;
	virtual void	Unk_42(void) = 0;
	virtual void	Unk_43(void) = 0;
	virtual void	Unk_44(void) = 0;
	virtual void	AddItem(TESForm* item, ExtraDataList* xDataList) = 0;
	virtual void	Unk_46(void) = 0;
	virtual void	Unk_47(void) = 0;
	virtual void	Unk_48(void) = 0;
	virtual MagicTarget *	GetMagicTarget(void) = 0;
	virtual void	Unk_4A(void) = 0;
	virtual void	Unk_4B(void) = 0;
	virtual void	Unk_4C(void) = 0;
	virtual void	Unk_4D(void) = 0;
	virtual void	Unk_4E(void) = 0;
	virtual void	Unk_4F(void) = 0;
	virtual void	Unk_50(void) = 0;	// 50
	virtual void	Unk_51(void) = 0;
	virtual void	Unk_52(void) = 0;			// inits animation-related data, and more
	virtual NiNode*	GenerateNiNode(void) = 0;
	virtual void	Set3D(NiNode* niNode);
	virtual NiNode *	GetNiNode(void) = 0;
	virtual void	Unk_56(void) = 0;
	virtual void	Unk_57(UInt32 arg0) = 0;
	virtual void	Unk_58(void) = 0;
	virtual void	Unk_59(void) = 0;
	virtual void	Unk_5A(void) = 0;
	virtual void	Unk_5B(void) = 0;
	virtual TESForm *	GetBaseForm(void) = 0;	// returns type this object references
	virtual float *	GetPos(void) = 0;
	virtual void	Unk_5E(void) = 0;
	virtual void	Unk_5F(void) = 0;
	virtual void	Unk_60(void) = 0;	// 60
	virtual void	Unk_61(void) = 0;
	virtual void	Unk_62(void) = 0;
	virtual UInt8	GetSleepState(void) = 0;
	virtual bool	IsActor(void) = 0;
	virtual void	ChangeCell(TESObjectCELL * newCell) = 0;
	virtual bool	IsDead(bool arg0) = 0;
	virtual void	Unk_67(void) = 0;
	virtual void	Unk_68(void) = 0;
	virtual void	Unk_69(void) = 0;

	TESChildCell	childCell;		// 018
	TESForm	* baseForm;				// 01C
										// U8(typeInfo + 4) == 0x23 is true if the object is a character
	float	rotX, rotY, rotZ;		// 020 - either public or accessed via simple inline accessor common to all child classes
	float	posX, posY, posZ;		// 02C - seems to be private
	float	scale;					// 038
	NiNode	* niNode;				// 03C
	TESObjectCELL	* parentCell;	// 040
	BaseExtraList	baseExtraList;	// 044

	ScriptEventList* GetEventList() const;
	bool IsTaken() const		{	return ((flags & kFlags_Taken) == kFlags_Taken) ? true : false;	}
	bool IsDeleted() const;
	void SetTaken(bool bTaken) {
		flags = (bTaken) ? (flags | kFlags_Taken) : (flags & ~kFlags_Taken);
	}
	bool	IsDisabled() { return flags & kFlags_Disabled ? true : false; }
	void	SetDisabled(bool bDisabled) {
		flags = bDisabled ? (flags | kFlags_Disabled) : (flags & ~kFlags_Disabled);
	}
	bool IsPersistent() { return (flags & kFlags_Persistent) ? true : false; }
	bool IsTemporary() { return (flags & kFlags_Temporary) ? true : false; }
	TESForm * GetInventoryItem(UInt32 itemIndex, bool bGetWares);
	void Disable();
	void Enable();
	bool RunScripts();		// runs magic effect and object scripts plus any scripts on items in inventory

	bool GetTeleportCellName(BSStringT* outName);
	bool Update3D();

	TESContainer* GetContainer();
	bool IsMapMarker();
	float GetDistance(TESObjectREFR* other, bool bIncludeDisabled);

	ExtraTeleport::Data* GetExtraTeleportData();

	static TESObjectREFR* Create(bool bTemp = false);
};

and in GameObjects.cpp

Spoiler

float TESObjectREFR::GetDistance(TESObjectREFR* other, bool bIncludeDisabled)
{
#if OBLIVION_VERSION == OBLIVION_VERSION_1_2_416
	float result;
	ThisStdCall(0x0065D270, this, other, bIncludeDisabled);
	__asm { fstp	[result] }
#else
#error unsupported Oblivion version
#endif
	return result;
}

With everything else that I do, usually I can do Actor/Reference->k_value or Actor/Reference->SomeFunction() if the value or function is a member of the calling class.

So logically, you would think that the following would work:

bool GetLOSAlt(Script* scriptObj, Actor * dActor, Actor * tActor){
... snip ...
		TESObjectREFR * dRef = (TESObjectREFR*)dActor;
		TESObjectREFR * tRef = (TESObjectREFR*)tActor;

		float distanceToTarget = dRef->GetDistance(tRef,1);
		float fScale = dRef->GetScale();
		
		if (distanceToTarget < dDetectLifeRange){bDetectLifeApplies = 1;}
		Console_Print("SDR dll: DL Check | Dist: %.4f | Scale: %.4f | Det: %s (%08X) | Targ: %s (%08X)"
			,distanceToTarget
			,fScale
			,GetFullName(dActor)
			,dActor ? dActor->refID : 0
			,GetFullName(tActor)
			,tActor ? tActor->refID : 0
			);
.... snip ...

I've tried it with just using the actor (because TESObjectREFR is a parent class) and also having the second argument be 0.
It compiles with no errors, however the result of distanceToTarget is always 0. But the fScale returns with an accurate result. Both functions are pulled from the exact same class structure.

Can someone please explain to me why?

Why?

Why the F does this NOT work??!!!

So bloody frustrating.

» Wed Apr 13, 2016 8:42 pm

Shot in the dark:


float distanceToTarget = dRef->GetDistance(*tRef,1);

» Thu Apr 14, 2016 3:11 am

Didn't work.

» Wed Apr 13, 2016 4:08 pm

Hmmm, Being a function it might want a double reference. Try &tref or **tref?

» Thu Apr 14, 2016 5:12 am

Unfortunately no.
With * I get: "No suitable conversion function from x to y exists" (where x is whatever form I'm inputting to the required form.)
With ** I get: "No operator "*" matches these operands"

However, I have discovered that TESObjectREFR->PosX (and PosY, and PosZ) works!
So I created a function that grabs the two positions of the two objects, uses some geometry, and calculates the distance between the two.

And it totally works. I'm getting the exact same distance as GetDistance.

Problem solved.

w00t!

P.S. What this means is that I now have an alternative version of GetLineOfSight which takes into account my various peripheral field of views per race/creature as well as impacts of helmets/hoods, and detect life.

So basically, if someone is looking in your direction, even if their vision is normally blocked, if they have an active detect life spell and you are within range, then they get LOS1. It's going to be much harder to escape detection from people that have detect life now.

» Wed Apr 13, 2016 11:07 pm

float GetDistance(NiAVObject* Object) {

Vector3 v;

v.x = Object->m_worldTranslate.x - (*g_thePlayer)->posX;

v.y = Object->m_worldTranslate.y - (*g_thePlayer)->posY;

v.z = Object->m_worldTranslate.z - (*g_thePlayer)->posZ;

return sqrt((v.x * v.x) + (v.y * v.y) + (v.z * v.z));

}

The example gets the distance of an object from the player.

» Wed Apr 13, 2016 2:15 pm

That's sort of what I ended up doing:


/*------------------------  Gets Distance between two sets of cooridnates  ---------------------------- */
float AltGetDistancePos(float x1, float y1, float z1, float x2, float y2, float z2)
{
	float squared = 2.0;
	float xx1 = x1-x2;
	float xx2 = pow(xx1,squared);
	float yy1 = y1-y2;
	float yy2 = pow(yy1,squared);
	float zz1 = z1-z2;
	float zz2 = pow(zz1,squared);
	return sqrt( xx2 + yy2 + zz2 );
}

/*------------------------  Gets Distance between two references  ---------------------------- */
float AltGetDistanceRefs(TESObjectREFR * ref1,TESObjectREFR * ref2)
{
		float x1 = ref1->posX;
		float y1 = ref1->posY;
		float z1 = ref1->posZ;
		float x2 = ref2->posX;
		float y2 = ref2->posY;
		float z2 = ref2->posZ;
		return AltGetDistancePos(x1, y1, z1, x2, y2, z2);
}

I need more flexibility than just the player though. I don't know if mine is necessarily better in terms of performance though. It's going to be called a lot, so it's a concern of mine.

» Thu Apr 14, 2016 3:44 am

This is a bug in OBSE code. If you check the implementation of GetDistance in GameObjects.cpp you'll find this:



float TESObjectREFR::GetDistance(TESObjectREFR* other, bool bIncludeDisabled)

{

#if OBLIVION_VERSION == OBLIVION_VERSION_1_2_416

    float result;

    ThisStdCall(0x0065D270, this, other, bIncludeDisabled);

    __asm { fstp    [result] }

#else

#error unsupported Oblivion version

#endif

    return result;

}

It simply calls a member function at 0x0065D270, which is not in TESObjectREFR code range.

What it actually calls is PlayerCharacter::GetActorValueModifier.

Probably by sheer luck the two functions have compatible signatures.

Otherwise you'd sure get CTD when calling it.

The correct function is at 0x004D7E90.

» Wed Apr 13, 2016 9:38 pm

So would I be better off with the correct function or just keep my code as is? It works as is at the moment.

» Thu Apr 14, 2016 4:33 am

@Tiawar: I have not the Oblivion database here, but IIRC, 0x0065D270 seems (as you say) a PlayerCharacter function.

Probably it is a copy&paste from an other function that has not been corrected.

» Wed Apr 13, 2016 4:44 pm

@saebel: if you are sure the refs are valid and in the same cell/worldspace, you can use your function. The getdistance vanilla function does only more checks before calculate the distance because it is made to be called from scripts or the console, so checks are required to ensure the refs and their state.

» Thu Apr 14, 2016 1:05 am

At the moment, I'm only planning on using it in two scenarios.

The first is detection checks. Since detection calls are only made by valid high processing actors against other valid high processing actors, I don't think it will be a problem.
The second is still a work/concept in progress where it has to deal with being in combat and whether or not they will continue to pursue the player. So in that particular case, the other actor has to be in combat with the player before the check is made.

The check is an alternative method to get line of sight that allows for extension beyond peripheral point of view as well as the detect life effect. Of course the actor must be within the range of the detect life spell and be detectable by it, so that's why I needed to get the distance between the two actors.
It returns 0 if definitely no line of site, 1 if traditional line of sight, 2 if line of sight in extended peripheral range, and 3 if line of sight through Detect Life magic only.
It works pretty good so far. I still have to finesse the detect life conditions a bit.

I did run some tests getting distances on actors that weren't anywhere near the player. It returned some insanely high number (blah blah blah E+38), which was what I was expecting. And since it didn't crash, I'm okay with that.

One glitch I discovered about GetLOS (the regular one) is that after you have killed an actor, even if you are blocked from view, it returns 1 if you are facing their direction. So if they were alive, under the same conditions it would normally return 0. Very odd.

I will also probably have to add in some checks for death state too, since there is a reverse line of sight call which should normally fail if the target is already dead.

» Thu Apr 14, 2016 5:14 am

Here's a simple wrapper you can use to call the internal function:

inline float GetRefDistance(TESObjectREFR *me, TESObjectREFR *other, bool allowDisabled = false)
{
    float distance;

    ThisStdCall(0x004D7E90, me, other, allowDisabled);

    __asm
    {
        fstp [distance]
    }

    return distance;
}

This will handle all cases of same cell/world or not.

As you have already discovered the game returns FLT_MAX if the distance between the two refs is undefined.

That's a constant you can test against.

float distance = GetRefDistance(ref1, ref2);

if (distance != FLT_MAX)
{
    // ok: refs are valid and in same cell/world
}
else
{
    // error: refs are not in same cell/world or ref2 is invalid (NULL, disabled or no parent cell/world)
}

» Wed Apr 13, 2016 8:28 pm

Ah yes, the functions under contention are all nicely listed https://github.com/JRoush/Common-Oblivion-Engine-Framework/blob/master/API/TESForms/TESObjectREFR.eed and https://github.com/JRoush/Common-Oblivion-Engine-Framework/blob/master/API/Actors/ActorValues.eed. Simple really.

» Wed Apr 13, 2016 10:33 pm

I know it sounds strange, and I do not want to interfere with OBSE development,

but wouldnt it make sense to use this functions in a OBSE addon, like a obse_math.dll, extending those functionality.

I do use this math every frame, determing the distance between two positions, xy, and xyz.

plus determing the angle in z direction.

It would be nice to have something like this in a common library.

We might keep distance from having too much redundant code.

I think this could be much faster than scripting, all in all.

Though I do not know what steps compiled code takes,

in comparison to OBSE functions and their functionality in scripting,

and native c++ code in OBSE dll.

» Wed Apr 13, 2016 4:23 pm

Well, I could split out my internal functions from my commands and make them available as common source code. That way all these bits that I have figured out or others have contributed can be used in other plugins.

Not all, of course, since some of the stuff that is specific to SDR would be useless. But there a number of functions that I have that either do math or replicate scripted functions that might be helpful.

If folks are interested, I'll see if I can't rearrange things a bit.

Perhaps call it open_toolbox.h and open_toolbox.cpp, indicating that those files could be dragged and dropped into any OBSE .dll solution and used.

Is that the sort of thing you mean?

Or are you talking about something that's more of an OBSEE. An extension of OBSE that is developed in common with commands that could be called from scripts?

I wouldn't be opposed to that either, but I wouldn't want to duplicate code in two places. Is it possible for one .dll to talk to another if there are multiple solutions? I'm still new at this.